OK, let's work through this together. We're starting with 54 and we're going to multiply it by 105, which means we add 54 to itself 105 times.
Step 1: 0 + 54 = 54
Step 2: 54 + 54 = 108
Step 3: 108 + 54 = 162
Step 4: 162 + 54 = 216
Step 5: 216 + 54 = 270
Step 6: 270 + 54 = 324
Step 7: 324 + 54 = 378
Step 8: 378 + 54 = 432
Step 9: 432 + 54 = 486
Step 10: 486 + 54 = 540
Step 11: 540 + 54 = 594
Step 12: 594 + 54 = 648
Step 13: 648 + 54 = 702
Step 14: 702 + 54 = 756
Step 15: 756 + 54 = 810
Step 16: 810 + 54 = 864
Step 17: 864 + 54 = 918
Step 18: 918 + 54 = 972
Step 19: 972 + 54 = 1026
Step 20: 1026 + 54 = 1080
Step 21: 1080 + 54 = 1134
Step 22: 1134 + 54 = 1188
Step 23: 1188 + 54 = 1242
Step 24: 1242 + 54 = 1296
Step 25: 1296 + 54 = 1350
Step 26: 1350 + 54 = 1404
Step 27: 1404 + 54 = 1458
Step 28: 1458 + 54 = 1512
Step 29: 1512 + 54 = 1566
Step 30: 1566 + 54 = 1620
Step 31: 1620 + 54 = 1674
Step 32: 1674 + 54 = 1728
Step 33: 1728 + 54 = 1782
Step 34: 1782 + 54 = 1836
Step 35: 1836 + 54 = 1890
Step 36: 1890 + 54 = 1944
Step 37: 1944 + 54 = 1998
Step 38: 1998 + 54 = 2052
Step 39: 2052 + 54 = 2106
Step 40: 2106 + 54 = 2160
Step 41: 2160 + 54 = 2214
Step 42: 2214 + 54 = 2268
Step 43: 2268 + 54 = 2322
Step 44: 2322 + 54 = 2376
Step 45: 2376 + 54 = 2430
Step 46: 2430 + 54 = 2484
Step 47: 2484 + 54 = 2538
Step 48: 2538 + 54 = 2592
Step 49: 2592 + 54 = 2646
Step 50: 2646 + 54 = 2700
Step 51: 2700 + 54 = 2754
Step 52: 2754 + 54 = 2808
Step 53: 2808 + 54 = 2862
Step 54: 2862 + 54 = 2916
Step 55: 2916 + 54 = 2970
Step 56: 2970 + 54 = 3024
Step 57: 3024 + 54 = 3078
Step 58: 3078 + 54 = 3132
Step 59: 3132 + 54 = 3186
Step 60: 3186 + 54 = 3240
Step 61: 3240 + 54 = 3294
Step 62: 3294 + 54 = 3348
Step 63: 3348 + 54 = 3402
Step 64: 3402 + 54 = 3456
Step 65: 3456 + 54 = 3510
Step 66: 3510 + 54 = 3564
Step 67: 3564 + 54 = 3618
Step 68: 3618 + 54 = 3672
Step 69: 3672 + 54 = 3726
Step 70: 3726 + 54 = 3780
Step 71: 3780 + 54 = 3834
Step 72: 3834 + 54 = 3888
Step 73: 3888 + 54 = 3942
Step 74: 3942 + 54 = 3996
Step 75: 3996 + 54 = 4050
Step 76: 4050 + 54 = 4104
Step 77: 4104 + 54 = 4158
Step 78: 4158 + 54 = 4212
Step 79: 4212 + 54 = 4266
Step 80: 4266 + 54 = 4320
Step 81: 4320 + 54 = 4374
Step 82: 4374 + 54 = 4428
Step 83: 4428 + 54 = 4482
Step 84: 4482 + 54 = 4536
Step 85: 4536 + 54 = 4590
Step 86: 4590 + 54 = 4644
Step 87: 4644 + 54 = 4698
Step 88: 4698 + 54 = 4752
Step 89: 4752 + 54 = 4806
Step 90: 4806 + 54 = 4860
Step 91: 4860 + 54 = 4914
Step 92: 4914 + 54 = 4968
Step 93: 4968 + 54 = 5022
Step 94: 5022 + 54 = 5076
Step 95: 5076 + 54 = 5130
Step 96: 5130 + 54 = 5184
Step 97: 5184 + 54 = 5238
Step 98: 5238 + 54 = 5292
Step 99: 5292 + 54 = 5346
Step 100: 5346 + 54 = 5400
Step 101: 5400 + 54 = 5454
Step 102: 5454 + 54 = 5508
Step 103: 5508 + 54 = 5562
Step 104: 5562 + 54 = 5616
Step 105: 5616 + 54 = 5670

So, 54*105 = 5670